In the production of elongated magnetic articles, such as axially leaded diodes, it has become customary to perform several manufacturing operations with the diodes positioned on a carrier wheel. The problem is to introduce the diodes into vacant positions on the wheel with high efficiency so that all positions are filled, particularly at the high rates of production expected today.
Heretofore, magnetic bins have been used to orient and suspend a supply of such diodes in a mutually parallel relationship in communication with the periphery of a carrier wheel. Such a bin has often been inclined toward the wheel so the diodes were urged into positions thereon. For moderate rates of position advancement, and where high efficiency in filling the positions has not been critical, the conventional magnetic bins have been satisfactory. Now, however, production rates of 50,000 to 70,000 diodes per hour are expected and filling efficiency is expected to be close to 100%. Therefore, new and improved apparatus and methods are indicated to meet the new expectations, particularly in diode packaging operations.
A copending application, Ser. No. 153,103, assigned to the assignee of this application, is believed pertinent to the instant invention and is hereby incorporated herein by reference. The incorporated application describes an operation for adhering diodes to tape for shipping purposes as follows: "Typically, such taping takes place by carrying the diodes in a closely spaced, parallel relationship on the periphery of a carrier wheel and by manipulating the tape such that it contacts a rather large portion of the periphery so that good adherence of the diodes to the tape is achieved. Typically, the wheel is loaded at a top portion and the taping takes place along a lower portion of the wheel.
It is advantageous to test the diodes on the same wheel which is used for taping to make certain each diode is electrically acceptable just before it is adhered to the tape. However, with the tape contacting the lower portion of the wheel, it becomes appropriate to do the testing and subsequent operations along the upper periphery of the wheel. Therefore, as the wheel rotates toward the tape, each diode is electrically tested and an unacceptable diode, for example, one having the wrong polarity is removed and replaced."
The incorporated application discloses an invention for automatically removing an unacceptable diode from the top portion of a carrier wheel. Consequently, such removal creates randomly located, vacant positions on the wheel which are desirably filled before taping takes place along the lower portion of the wheel. Heretofore, it is believed that such filling has typically been done on a manual basis, often with the wheel being stopped for this purpose. Now, a desire to enhance the speed of diode manufacture has inspired efforts to automatically introduce diodes into the vacant positions without stopping the wheel.
Vacant positions on a carrier wheel are typically filled as the periphery of the wheel is advanced in an ascendent path so that diodes which are not in position tend to return to the bin or to wheel positions under the force of gravity. The problem in filling vacant positions which occur between testing and taping is that such filling is to be done as the periphery of the wheel advances in a descendant path and gravity works against such filling. Furthermore, the diodes are to be introduced into such randomly occurring positions without dislodging closely spaced, adjacent diodes which have been successfully tested and are ready for taping.